This application claims the benefit to German Application No. 10032656.0, filed Jun. 28, 2000, the contents of which are hereby incorporated by reference.
The invention relates to the field of electrical switches, and in particular, to the physical design of bushings such as those used in gas-insulated, encapsulated high-voltage systems for the current-carrying junction between a system and an overhead line or a transformer.
Outdoor bushings of this type normally comprise a hollow insulator having a high-voltage connection arranged at the upper end of the insulator and having a foot part which grips the lower end of the insulator and is provided with a mounting flange, and an electrical conductor running in the axial direction of the insulator. The annular foot part of such a bushing is bonded or mechanically joined to the lower end of the insulator and has a mounting flange for mounting the insulator on a corresponding connecting flange of an encapsulating housing of the high-voltage system (DE 27 48 002 A1, U.S. Pat. No. 4,358,631A), or on a mounting flange of a tubular adapter associated with the encapsulating housing of a high-voltage system.
In order to maintain the necessary minimum separations between the outdoor connections that are at high-voltage potential, both for single-phase and polyphase switchgear assemblies at relatively high voltage levels and with the horizontally arranged switching devices being constructed to be as short as possible, it is normal to arrange the high-voltage bushings inclined to the vertical.
To this end, the switching devices may themselves be provided with connecting flanges inclined to the horizontal (EP 0 744 758 A2, U.S. Pat. No. 4,016,382A) orxe2x80x94if the connecting plane of the switching device flange runs horizontallyxe2x80x94curved tubes may be connected in between, whose connecting flange associated with the high-voltage bushing is inclined to the horizontal (DE 39 15 699 A1). In order for such a switching device to have as small a transport volume as possible, it is also known not only to have the connecting flanges of the switching device be inclined horizontally, but also for curved tubes to be connected between the switching device and the high-voltage bushings. In the tubes, the flange plane of the connecting flange is likewise inclined to horizontally (U.S. Pat. No. 4,016,382A).
In one embodiment of the invention, there is an outdoor high-voltage bushing for an encapsulated high-voltage system. The invention includes, for example, a hollow insulator having a high-voltage connection arranged at the upper end; a foot part which grips the lower end and is provided with a mounting flange; and an electrical conductor running in the axial direction of the insulator, wherein the foot part is in the form of a curved housing part, in which the flange plane of the mounting flange is inclined at an angle, which is about less than 90xc2x0, to the axis of the insulator, and a post insulator is arranged in the foot part, on which a contact piece is mounted for connection of the electrical conductor and for connection of a current path of the encapsulated high-voltage system.
In another embodiment of the invention, there is an encapsulated high-voltage switching device arranged horizontally. The invention includes, for example, a horizontally arranged, tubular encapsulating housing with feeders and outgoers arranged transversely with respect to the axis of the encapsulating housing, the encapsulating housing having a connecting sleeve with a connecting flange for each feeder and outgoer, and each connecting flange having an associated outdoor high-voltage bushing, wherein a flange plane of at least one connecting flange is arranged horizontally, and the at least one connecting flange having an associated outdoor high-voltage bushing.
In one aspect of the invention, the outdoor high-voltage bushing comprises a hollow insulator having a high-voltage connection arranged at the upper end; a foot part which grips the lower end and is provided with a mounting flange; and an electrical conductor running in the axial direction of the insulator, wherein the foot part is in the form of a curved housing part, in which the flange plane of the mounting flange is inclined at an angle, which is about less than 90xc2x0, to the axis of the insulator, and a post insulator is arranged in the foot part, on which a contact piece is mounted for connection of the electrical conductor and for connection of a current path of the encapsulated high-voltage system.